ComputeSignature(byte[] key, byte[] buf)
{
using (HMACSHA512 hmac = new HMACSHA512(key))
{
byte[] signature = hmac.ComputeHash(buf);
BufArray.Wipe0(hmac.Key);
// wipe key?
return(signature);
}
}
Verify(byte[] key, byte[] buf)
{
if (key == null)
{
throw new ArgumentException("Hmac key must not be null.");
}
if (buf == null | buf.Length < Hmac512.SignatureByteLength + 1)
{
throw new ArgumentException("Hmac input buffer's length is too short or null.");
}
using (HMACSHA512 hmac = new HMACSHA512(key))
{
// Skip the prepended hmac signature.
byte[] computedSignature = hmac.ComputeHash(
buf, Hmac512.SignatureByteLength,
buf.Length - Hmac512.SignatureByteLength
);
bool ret;
if (!BufArray.Compare(
buf, 0,
computedSignature, 0,
Hmac512.SignatureByteLength)
)
{
ret = false;
}
else
{
ret = true;
}
BufArray.Wipe0(hmac.Key);
return(ret);
}
}